Piston



H. D. CHURCH Feb. 15, 1938.

PISTON Filed Jan. 9, 1935 Patented Feb. 15, 1938 IT ED STATES,

PISTON Harold D. Church, Cleveland, Ohio, assignor to General MotorsCorporation, Detroit, Mich., a

corporation of Delaware Application January 9, l935,- Serial No. 947Claims. (01. 309-8) To void the bad effects of heat localization it hasbeen proposed to provide the piston of. an internal combustion enginewith a splash pocket to contain a body of heat exchanging medium,

againstthe interior surfaces of the head and skirt and absorbs heat fromthe normally hot head and passes it into the normally cool skirt fortransfer through the cylinder wall and dissipation in the usual enginecooling system. The result is that the head and skirt run at more nearlythe same temperature and heat is readily exheaded end of the piston forthe return to the supply sump of excess oil scraped from the cylinderwall.

The present invention has for its object the provision, in a simple andeconomical fashion, of

, means to by-pass or bridge the cooling well and convey oil scrapedfrom the cylinder during piston movement for discharge into the enginecrankcase. More specifically, the invention involves the provision in apiston with an interior pocket and exterior packing rings, of a seriesof circum- 5 ferentially spaced drain tubes extending downwardly andinwardly across the cooling chamber from. the piston wall adjacent oneof the packing rings, to a point beyond the baffle. Each tube has itsopposite ends projected through and supported by the baffle and wall ofthe piston respectively, and its piston wall end is headed or providedwith a peripheral enlargement to seat within a shouldered bore formed inthe skirt of the piston in intersecting relation with a pack ing ringgroove, whereby it is held against displacement by the ring within thegroove.

The invention will be understood best upon reference to-the accompanyingdrawing, wherein Figures 1 and 2 are vertical sectional views at rightangles to each other of a piston embodying the improved drain; Figure 3is a transverse section taken on line 3-3 of Figure 1, and Figure 4 isadetail section on line 4-4 of Figure 3, of one of the drain tubes on anenlarged scale.

' Only so much of an engine as is necessary to which in thereciprocation of the piston is thrown,

illustrate the invention is shown in the drawing. It will be understoodthat the engine may have a number of cylinders, each with its pistonoperatively connected with the crankshaft, andthat an engine driven pumpdelivers oil from the crankcase under pressure to the several hearings,including the piston pin bearings which receive their supply through apassageway in the connecting rod. 1

For convenience, the hollow piston is shown at t'op'dead center positionwithin the cylinder I, which may be either air or water cooled, a Waterjacket 2 being illustrated. The piston comprises a head 3 and a skirt 4,together with bosses- 5, in which is located the pin 6 for journalingthe 15 upper end of a connecting rod 1. A drilled pas sageway 8 in therod supplies oil tothe journal bearing and also against the interior of.the piston through a nozzle 9 carried at the top of the rod.-.

The oil supplied through the nozzle 9 drops 20 into and is trapped by anannular pocket formed, in cooperation with the skirt 4, by a baflle 'ordomed sleeve l0 of sheet metal, which receives interiorly thereof, theend of the rod 1 and extends throughout substantially the length of theskirt in spaced relation thereto. The bafiie may be secured to thepiston pin bosses by studs I l and at its lower end is flared outwardlyto form a skirt engaging rim l2. At its upper end the sleeve has anelongated opening defined by upstand- 30 ing flanges I3, toallow,movement of the nozzle 9 during rocking movement of the connectingrod, and which movement causes the oil to be sprayed against variousportionsof the underside of the head 3. To increase the heat radiatingsurface, 35

the underside of the head may carry a number of fins Id. The heatabsorbed at the head by the body of oil splashed back and forth istransferred into the skirt and through the cylinder wall to the waterwithin the cooling jacket 2. So that there may be a constant change ofoil within the pocket, one or more outlet openings l5 may be provided inthe bafile ill, the size of which will be predetermined to allow ametered discharge,.

whereby a given quantity of oil will be maintainecl within the pocket atall times.

Near opposite ends of thepiston skirt there are cut the .usual groovesto receive an upper group therewith an oil collecting pocket immediatelybe- 55 low the ring, from which one or more drain openings I! (seeFigure ,1) lead inwardly for the return of oil to the engine crankcase.A similar oil collecting pocket adjacent. the lowermost groove for theupper set of rings I6 is provided by an annular recess l9 from whichleads a series of inclined drain tubes 20 bridging the interior coolingjacket.

As best seen in Figure 4, the inner end of each tube projects through anopening in the baflie and discharges beyond the pocket or interiorly ofthe hollow baille or sleeve ID for the return of oil by free gravityflow to the engine crankcase. The opposite end of the tube 20 has anenlarged head 2| which seats against a shoulder in an opening drilleddownwardly and inwardly through the skirt in intersecting relation withthe lowermost ring groove of the upper group. Thus when the packing ringis inserted within the groove it extends over the head 2| and preventsoutward displacement of the tube.

From theabove description it will be apparent that there is thusprovided a drain particularly adapted for use with a piston having acooling pocket, and which is extremely'simple in design and easy tomanufacture at low cost.

I claim: 1

1. In a piston of the character described, a skirt having near theheaded end thereof a packing ring groove, and a series of shoulderedbores extending downwardly and inwardly in intersecting relation withthe groove, a series of drain tubes. each having anenlargement seatingin said shouldered bore and a packing ring in said groove holding thetubes against displacement.

2. In a piston of the character described, a skirt having a groove foran oil collecting ring and a downwardly and inwardly directed shoulderedbore leading from and opening into said ring groove, a headed conduitadapted to be fitted in the bore through said ring groove with its headseated on the shoulder against inward displacement, and a ring receivedwithin said groove over the headed conduit to retain the conduit againstoutward displacement. I

3. A piston having a ring groove in the headed end thereof and a,conduit projected from the groove and being characterized by ashouldered passage extending downwardly in intersectingin overlappingrelation with the headed end of the conduit.

5. In a piston assembly of the character described, aperipheral groovein the wall of the piston, a series of shouldered passages extendingdiagonally downward from the ring groove in intersecting relationtherewith, a removable headed conduit projecting inwardly through eachpassage and having its headed end seated in the shouldered passage and apiston ring fitted to said peripheral groove in overlapping retainingrelation to the headed end of the conduit.

HAROLD D. CHURCH.

